08/25/2008 at 09:00 AM EDT
So what's it like for Demi Lovato to be on tour with the Jonas Brothers
"They always have my back," Lovato, 15, said before a performance Saturday at Arthur Ashe Kids Day at the U.S. Open in New York. "They're very protective."
Kevin Jonas, 20, makes sure she has her water. Joe, 19, helps the self-professed klutz stay upright onstage, pointing out steps and other things that might trip her.
"I'm very uncoordinated," said Lovato as a gaggle of her elementary school and 'tween fans screamed from the stands. "I'm surprised I don't fall onstage more. They're like, 'Watch your step.' "
Lovato – who said she is "definitely not dating anyone" at the moment – said the Jonas Brothers amaze her.
"They're 10 times more cool when you meet them and hang out with them all the time," she said. "They're hilarious."